diff options
| author | Ye Bin <yebin10@huawei.com> | 2022-09-14 18:08:12 +0800 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2022-09-30 23:46:52 -0400 |
| commit | 243d1a5d505d0b0460c9af0ad56ed4a56ef0bebd (patch) | |
| tree | 03104b6889bdf97ca76bd508ab80c03f1838d4af | |
| parent | e0d5fc7a6d80ac2406c7dfc6bb625201d0250a8a (diff) | |
jbd2: fix potential use-after-free in jbd2_fc_wait_bufs
In 'jbd2_fc_wait_bufs' use 'bh' after put buffer head reference count
which may lead to use-after-free.
So judge buffer if uptodate before put buffer head reference count.
Cc: stable@kernel.org
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20220914100812.1414768-3-yebin10@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| -rw-r--r-- | fs/jbd2/journal.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index d00193077bce..bc8270e0d7d0 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -923,16 +923,16 @@ int jbd2_fc_wait_bufs(journal_t *journal, int num_blks) for (i = j_fc_off - 1; i >= j_fc_off - num_blks; i--) { bh = journal->j_fc_wbuf[i]; wait_on_buffer(bh); - put_bh(bh); - journal->j_fc_wbuf[i] = NULL; /* * Update j_fc_off so jbd2_fc_release_bufs can release remain * buffer head. */ if (unlikely(!buffer_uptodate(bh))) { - journal->j_fc_off = i; + journal->j_fc_off = i + 1; return -EIO; } + put_bh(bh); + journal->j_fc_wbuf[i] = NULL; } return 0; |